Digital camera including a distortion correction system

ABSTRACT

A digital camera system includes a camera body; a lens mounted to the camera body, and an image processor operatively coupled to the lens. The image processor converts a visual image passing into the lens to a digital format to form a captured digital image. The digital camera system also includes an angle sensor mounted in the camera body. The angle sensor, in the form of a multi-spot focus angle sensor, determines a camera angle position and outputs camera angle position data. A distortion processor operatively coupled to the digital camera receives the camera angle position data obtained from the sensor and the captured digital image from the image processor to selectively remove distortions associated with the camera angle position to form a corrected digital image.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the art of digital camera systems and, moreparticularly, to a digital camera system including an angle sensoremployed in connection with an image distortion correction process.

2. Description of Background

In the art of photography, image distortions are a common occurrence.Various lens configurations, e.g., telephoto lenses, wide-angle lensesand the like, cause distortions in captured images. Conventionally,photographers either avoided using outer magnification ranges of thelenses to avoid distortion effects or expected viewers to simply acceptthe poor picture quality. Over time, specialty lenses were developed toaddress the distortion effects. The specialty lenses minimized orcorrected distortions at the outer magnification ranges. Unfortunately,the specialty lenses currently available are expensive and often timesdifficult to use.

At present, more modern digital cameras are rapidly replacingconventional cameras. Image distortion, however, remains an issue.Digital cameras typically address image distortions through postprocessing techniques. More specifically, after capturing a digitalimage of an object, the camera is connected to a computer including aprocessing software package. The digital image is downloaded onto thecomputer and processed by the processing software to correct distortionsas necessary. However, removing distortions with processing software canbe very cumbersome. The software programs currently available arecomplicated, often times requiring much trial and error on the part of auser until a desired output is obtained.

SUMMARY OF THE INVENTION

The shortcomings of the prior art are overcome and additional advantagesare provided through the provision of a digital camera system includinga camera body; a lens mounted to the camera body, and an image processoroperatively coupled to the lens and the display. The image processorconverts a visual image passing into the lens to a digital format toform a captured digital image. The digital camera system also includesmulti-spot angle sensor mounted in the camera body. The angle sensordetermines a camera angle position by measuring relative lengths of aplurality of beams passing between the camera body and an object to bephotographed, and outputs camera angle position data. A distortionprocessor operatively coupled to the digital camera receives the cameraangle position data obtained from the sensor, and the captured digitalimage from the image processor to selectively remove distortionsassociated with the camera angle position to form a corrected digitalimage.

Additional features and advantages are realized through the techniquesof the present invention. Other embodiments and aspects of the inventionare described in detail herein and are considered a part of the claimedinvention. For a better understanding of the invention with advantagesand features, refer to the description and to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter, which is regarded as the invention, is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other objects, features, andadvantages of the invention are apparent from the following detaileddescription taken in conjunction with the accompanying drawings inwhich:

FIG. 1 illustrates one example of a digital camera system including anangle sensor constructed in accordance with an exemplary embodiment ofthe present invention; and

FIG. 2 is a flow diagram illustrating an image capture and distortioncorrection process of the exemplary embodiment.

The detailed description explains the preferred embodiments of theinvention, together with advantages and features, by way of example withreference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Turning now to the drawings in greater detail, it will be seen that inFIG. 1 there is a digital camera system indicated generally at 2. Camerasystem 2 includes a digital camera 3 having a main body 4 provided witha lens member 6 and a display portion 9. In addition, camera 3 includesa capture button 12 which, as will be discussed more fully below, isactivated to capture an image of an object to be photographed, such asindicated generally at 15. Camera 3 also includes a features button 20that enables a user to change various settings for capturing pictures,storing pictures, processing pictures, and the like and an input/outputor I/O port 23 that provides an interface for external devices, such aspersonal computers and portable media storage devices.

In accordance with the exemplary embodiment shown, camera system 2includes in image capture system 30 that captures and formats digitalimages of the object being photographed. More specifically, imagespassing through lens member 6 are passed to a controller or centralprocessing unit (CPU) 40 and onto to an image processor 42 which covertsthe captured image to a digital format. In addition, camera 3 isprovided with a tilt or angle sensor 44 that obtains camera angle datarepresentative of an angle of camera 3 relative to the object beingphotographed. Angle sensor 44 can be formed from a variety of variousposition-type sensors such as a mercury-like sensor, a pendulum sensoror a micro electro-mechanical system or MEMS sensor to detect an up/downtilt of camera 3. In addition, sensor 44 can be a multi-spot focusarrangement that sends out multiple beams, usually infrared, such asindicated at 46 a-46 e. Measuring a length of each beam 46 a-46 e,sensor 44 calculates relative distances to the object to be photographedand determines an angle of camera 3. Camera system 2 is also operativelycoupled to a distortion processor 45 that employs the camera angle dataobtained from angle sensor 44 to correct image distortions in thecaptured image. Camera system 2 is also shown to be coupled to a memory48 which stores captured and/or corrected digital images of the objectbeing photographed.

At this point, it should be understood that while illustrated as a CPU,controller 40 could include any appropriate high-powered solid-stateswitching device. It should also be appreciated by those skilled in theart, that controller 40 can be a separate dedicated or programmableintegrated or other electronic device such as a personal computer or thelike. In general, any device or similar devices capable of implementingthe flow charts as illustrated in the application can be used ascontroller 40.

At this point, reference will be made to FIG. 2 in describing an imagecapture and distortion correction process 57 in accordance with anexemplary embodiment of the invention. In order to capture an image ofan object to be photographed, lens member 6 is aimed toward, or directedat the object, as indicated in block 60. At this point, capture button12 is activated to capture an image of the object to be photographed, asindicated in block 62. Once captured, the image is passed to imageprocessor 19 in as indicated in block 63. Simultaneously with capturingthe image of the object, image capture and distortion correction process57 collects angle data representative of the angle of camera 3 relativeto the object as indicated in block 64. In accordance with one aspect ofthe exemplary embodiment, the angle data obtained through sensor 34 isembedded as a digital header of the captured image in block 67. At thispoint, the captured image and camera angle data are passed to a memory48 carried within digital camera 3 as indicated in block 70.Alternatively, the captured image and angle data can be passed to anexternal memory.

In accordance with aspect of the invention, the captured image and angledata are passed to a distortion correction portion 80. Distortioncorrection portion 80 can be carried internally in camera 3 or,alternatively, be part of an external photo processing software system.In any event, the captured image and angle data are passed to distortionprocessor 45 in block 83. Distortion processor 45 utilizes the angledata collected in block 64 to correct the image captured in block 62. Inone example, distortion processor 45 will digitally stretch a portion ofthe captured image to adjust for, or correct, any distortions resultingfrom the angle of camera 3. In any event, after processing, a correctedimage is created in block 86. The corrected image is then passed back tomemory 48 for further processing by the user. That is, at this point theuser can elect to save the corrected image, print a digital photograph,or send to a company for processing. In addition, distortion processor45 can also output a captured image as indicated in block 88. Thecaptured image includes the angle data in a digital header. In thismanner, the user is provided with the option of viewing the image asactually captured or saving the captured image for later processing. Inaddition, by storing angle data in the digital header, after thecorrected image is formed, distortion processor 64 can be employed toundo or remove corrections to the captured image such as indicated inblock 90. That is, if the user desires to return from the correctedimage to the captured image, camera 3 includes an “undo” option.

In any event, it should be appreciated that the present inventionprovides for a relatively simple and cost-effective arrangement forcorrecting camera angle distortions in a digital camera system withoutrequiring a great deal of trial and error by a user. That is, the systemcorrects for camera angle distortions without requiring multiplemanipulations or extensive training on the part of the user. In anycase, it should also be appreciated that the flow diagrams depictedherein are just examples. There may be many variations to these diagramsor the steps (or operations) described therein without departing fromthe spirit of the invention. For instance, the steps may be performed ina differing order, or steps may be added, deleted or modified. The stepscould be performed wholly within the camera or a portion of the stepscould be preformed outside the camera using externals photo processingsoftware. All of these variations are considered a part of the claimedinvention.

While the preferred embodiment to the invention has been described, itwill be understood that those skilled in the art, both now and in thefuture, may make various improvements and enhancements which fall withinthe scope of the claims which follow. These claims should be construedto maintain the proper protection for the invention first described.

1. A digital camera system comprising: a camera body; a lens mounted tothe camera body; an image processor operatively coupled to the lens, theimage processor converting a visual image passing into the lens to adigital format to form a captured digital image; a multi-spot focusangle sensor mounted in the camera body, the sensor determining a cameraangle position by measuring relative lengths of a plurality of beamspassing between the camera body and an object to be photographed andoutputting camera angle position data; a distortion processoroperatively coupled to the digital camera, the distortion processorreceiving the camera angle position data obtained from the angle sensorand the captured digital image from the image processor, the distortionprocessor selectively removing distortions associated with the cameraangle position to form a corrected digital image; and a single memoryoperatively connected to the distortion processor and the imageprocessor, the single memory permanently storing the captured digitalimage and the corrected digital image, wherein the camera angle positiondata is stored as a picture file header associated with the captureddigital image, the distortion processor selectively employing the cameraangle position data in the picture file header to form the correcteddigital image and to remove corrections from a corrected digital image.2. The digital camera system according to claim 1, wherein thedistortion processor is mounted in the camera body.
 3. The digitalcamera system according to claim 1, wherein the distortion processor ismounted remote from the camera body.